Avalanche Forecast

Issued: Mar 12th, 2012 3:43PM

The alpine rating is high, the treeline rating is high, and the below treeline rating is considerable. Known problems include Persistent Slabs, Wind Slabs and Deep Persistent Slabs.

Aaron Beardmore, Parks Canada

Banff Yoho Kootenay.

Up to 25cm of snow is expected overnight and into tomorrow morning. The additional load will push the danger rating to HIGH. Be vigilant and observant tomorrow. Expect to see natural avalanches occurring.

Summary

Weather Forecast

Snowpack Summary

Avalanche Summary

Confidence

Forecast snowfall amounts are uncertain on Tuesday

Problems

Persistent Slabs

A slab overlies the Feb 14 surface hoar down 60-100 cm. This layer will be loaded with up to 25cm of storm snow by Tuesday afternoon. Expect natural activity and an increased potential for human triggering.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 4

Wind Slabs

The expected snow and associated wind throughout Monday night will produce wind-slabs up to 30cm deep in lee areas at high elevations.

Aspects: North, North East, East, South East.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

Slabs starting on the Feb 14 layer can step down, triggering deep slabs. When triggered, these large and destructive avalanches will slide on basal facets close to the ground. Fracture lines could be up to 200cm deep with wide propagations.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 4

Valid until: Mar 13th, 2012 5:00PM